There is a very easy way to tell what type of tegu you have. If you look at the head on an Argentine there will be two distinct scales between the eye and the nostril. There will only be one scale on the columbian. Look at the attatched photo of my Argentine, See the two scales if yours looks like this you have an Argentine if not you have a columbian. Do not pay attention to colors as they share similar coloring that varies from lizard to lizard.
To post pics go to the top of the page at kingsnake and find the photo gallery link. Once there go to upload photo link. You will need to sign in and follow the directions on the page and walla you have a pic you can attatch to your posts. Good luck and let us know what you got.

-----
Beau W.
"There are no athiests in foxholes. It is not an argument against athiesm but rather one against foxholes." James Morrow